Chapter 11 A&P Nervous System PDF

Chapter 11 A&P -- Nervous System: Spinal cord and Peripheral nerves I. Spinal cord -- Structure a. Continuation of brainstem -- extends from foramen magnum to L1 b. Tube-like structure located in the spinal cavity c. Protected by bone, meninges, and CSF d. Gray matter -- lo...

Chapter 11 A&P -- Nervous System: Spinal cord and Peripheral nerves I. Spinal cord -- Structure a. Continuation of brainstem -- extends from foramen magnum to L1 b. Tube-like structure located in the spinal cavity c. Protected by bone, meninges, and CSF d. Gray matter -- located in the center and butterfly shapes i. Central canal -- in the middle of the gray matter, CSF flows through this e. White matter ii. Sensory tracts (ascending tracts) -- sensory (afferent) nerve 1. Carry information from PNS to CNS iii. Motor tracts (descending tracts)-motor (efferent) nerve 2. Carry information from CNS to PNS 3. Decussate -- term used when referring to crossover of tracts f. Spinal cord injury iv. Quadriplegia -- spinal cord is severed at neck region causing paralysis of all 4 extremities v. Paraplegia -- spinal cord is injured lower than neck region causing paralysis of lower extremities II. Spinal cord -- Function g. 3 major functions vi. Sensory pathway vii. Motor pathway viii. Reflex center III. Reflexes h. What are reflexes ix. Involuntary response to stimuli i. Common reflexes x. Babinski -- stroke sole heel to toe --positive causes dorsiflexion of big toe, normal in infancy xi. Knee-jerk reflex xii. Baroreceptor reflex -- controls BP j. Reflex Arc xiii. The pathway of a reflex response xiv. Sensory receptor \> sensory neuron \>motor neuron \> effector organ IV. Peripheral nervous system k. Nerves and ganglia located outside the CNS l. Neuron is a single nerve cell m. Nerve contains many neurons n. Classifying PNS xv. Cranial and Spinal nerves 4. Cranial Nerves -- 12 pairs a. Each cranial nerve has a specific number indicating the order in which the nerve exits the brain b. I -- Olfactory -- smell c. II -- Optic -- sight d. III -- Oculomotor -- movement of eye structure e. IV -- Trochlear -- movement of eyeball f. V -- trigeminal -- chewing, face sensations g. VI -- Abducens -- movement of eyeball h. VII-- Facial -- facial expressions, blinking, saliva, tears, taste i. VIII -- Vestibulocochlear -- hearing and balance j. IX -- Glossopharyngeal -- swallowing, taste, gag reflex k. X -- Vagus -- visceral muscle movement, reflex regulation of BP l. XI -- Accessory -- swallowing, speaking m. XII -- hypoglossal -- speech and swallowing 5. Spinal Nerves n. Attached to spinal cord o. Two roots i. Dorsal-contains sensory fibers ii. Ventral -- contain motor fibers p. Names and numbers iii. 31 pairs grouped 1. 8 pairs of cervical nerves 2. 12 pairs of thoracic nerves 3. 5 pairs of lumbar nerves 4. 5 pairs of sacral nerves 5. 1 pair of coccygeal nerves iv. Spinal Nerves Plexuses 6. Cervical a. Supply muscles and skin of neck b. Phrenic nerve location c. Injured at C2 or above- affects phrenic nerve and diaphragm 7. Brachial d. Supply muscles and skin of shoulder, arm, forearm, wrist, and hand 8. Lumbosacral e. Supply muscle and skin of lower abdominal wall, external genitalia, buttocks, and lower extremities v. Dermatome 9. Area where dorsal root innervates to a particular area of the skin 10. Important clinically when finding nerve impairment